1 /*
2 * GRUB -- GRand Unified Bootloader
3 * Copyright (C) 2000, 2001 Free Software Foundation, Inc.
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18 */
19
20 /*
21 * Elements of this file were originally from the FreeBSD "biosboot"
22 * bootloader file "disk.c" dated 4/12/95.
23 *
24 * The license and header comments from that file are included here.
25 */
26
27 /*
28 * Mach Operating System
29 * Copyright (c) 1992, 1991 Carnegie Mellon University
30 * All Rights Reserved.
31 *
32 * Permission to use, copy, modify and distribute this software and its
33 * documentation is hereby granted, provided that both the copyright
34 * notice and this permission notice appear in all copies of the
35 * software, derivative works or modified versions, and any portions
36 * thereof, and that both notices appear in supporting documentation.
37 *
38 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
39 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
40 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
41 *
42 * Carnegie Mellon requests users of this software to return to
43 *
44 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
45 * School of Computer Science
46 * Carnegie Mellon University
47 * Pittsburgh PA 15213-3890
48 *
49 * any improvements or extensions that they make and grant Carnegie Mellon
50 * the rights to redistribute these changes.
51 *
52 * from: Mach, Revision 2.2 92/04/04 11:35:49 rpd
53 * $Id: fsys_ffs.c,v 1.1.1.1 2003/11/20 02:04:59 fengshuo Exp $
54 */
55
56 #ifdef FSYS_FFS
57
58 #include "shared.h"
59
60 #include "filesys.h"
61
62 #include "defs.h"
63 #include "disk_inode.h"
64 #include "disk_inode_ffs.h"
65 #include "dir.h"
66 #include "fs.h"
67
68 /* used for filesystem map blocks */
69 static int mapblock;
70 static int mapblock_offset;
71 static int mapblock_bsize;
72
73 /* pointer to superblock */
74 #define SUPERBLOCK ((struct fs *) ( FSYS_BUF + 8192 ))
75 #define INODE ((struct icommon *) ( FSYS_BUF + 16384 ))
76 #define MAPBUF ( FSYS_BUF + 24576 )
77 #define MAPBUF_LEN 8192
78
79
80 int
ffs_mount(void)81 ffs_mount (void)
82 {
83 int retval = 1;
84
85 if ((((current_drive & 0x80) || (current_slice != 0))
86 && ! IS_PC_SLICE_TYPE_BSD_WITH_FS (current_slice, FS_BSDFFS))
87 || part_length < (SBLOCK + (SBSIZE / DEV_BSIZE))
88 || !devread (SBLOCK, 0, SBSIZE, (char *) SUPERBLOCK)
89 || SUPERBLOCK->fs_magic != FS_MAGIC)
90 retval = 0;
91
92 mapblock = -1;
93 mapblock_offset = -1;
94
95 return retval;
96 }
97
98 static int
block_map(int file_block)99 block_map (int file_block)
100 {
101 int bnum, offset, bsize;
102
103 if (file_block < NDADDR)
104 return (INODE->i_db[file_block]);
105
106 /* If the blockmap loaded does not include FILE_BLOCK,
107 load a new blockmap. */
108 if ((bnum = fsbtodb (SUPERBLOCK, INODE->i_ib[0])) != mapblock
109 || (mapblock_offset <= bnum && bnum <= mapblock_offset + mapblock_bsize))
110 {
111 if (MAPBUF_LEN < SUPERBLOCK->fs_bsize)
112 {
113 offset = ((file_block - NDADDR) % NINDIR (SUPERBLOCK));
114 bsize = MAPBUF_LEN;
115
116 if (offset + MAPBUF_LEN > SUPERBLOCK->fs_bsize)
117 offset = (SUPERBLOCK->fs_bsize - MAPBUF_LEN) / sizeof (int);
118 }
119 else
120 {
121 bsize = SUPERBLOCK->fs_bsize;
122 offset = 0;
123 }
124
125 if (! devread (bnum, offset * sizeof (int), bsize, (char *) MAPBUF))
126 {
127 mapblock = -1;
128 mapblock_bsize = -1;
129 mapblock_offset = -1;
130 errnum = ERR_FSYS_CORRUPT;
131 return -1;
132 }
133
134 mapblock = bnum;
135 mapblock_bsize = bsize;
136 mapblock_offset = offset;
137 }
138
139 return (((int *) MAPBUF)[((file_block - NDADDR) % NINDIR (SUPERBLOCK))
140 - mapblock_offset]);
141 }
142
143
144 int
ffs_read(char * buf,int len)145 ffs_read (char *buf, int len)
146 {
147 int logno, off, size, map, ret = 0;
148
149 while (len && !errnum)
150 {
151 off = blkoff (SUPERBLOCK, filepos);
152 logno = lblkno (SUPERBLOCK, filepos);
153 size = blksize (SUPERBLOCK, INODE, logno);
154
155 if ((map = block_map (logno)) < 0)
156 break;
157
158 size -= off;
159
160 if (size > len)
161 size = len;
162
163 disk_read_func = disk_read_hook;
164
165 devread (fsbtodb (SUPERBLOCK, map), off, size, buf);
166
167 disk_read_func = NULL;
168
169 buf += size;
170 len -= size;
171 filepos += size;
172 ret += size;
173 }
174
175 if (errnum)
176 ret = 0;
177
178 return ret;
179 }
180
181
182 int
ffs_dir(char * dirname)183 ffs_dir (char *dirname)
184 {
185 char *rest, ch;
186 int block, off, loc, map, ino = ROOTINO;
187 struct direct *dp;
188
189 /* main loop to find destination inode */
190 loop:
191
192 /* load current inode (defaults to the root inode) */
193
194 if (!devread (fsbtodb (SUPERBLOCK, itod (SUPERBLOCK, ino)),
195 ino % (SUPERBLOCK->fs_inopb) * sizeof (struct dinode),
196 sizeof (struct dinode), (char *) INODE))
197 return 0; /* XXX what return value? */
198
199 /* if we have a real file (and we're not just printing possibilities),
200 then this is where we want to exit */
201
202 if (!*dirname || isspace (*dirname))
203 {
204 if ((INODE->i_mode & IFMT) != IFREG)
205 {
206 errnum = ERR_BAD_FILETYPE;
207 return 0;
208 }
209
210 filemax = INODE->i_size;
211
212 /* incomplete implementation requires this! */
213 fsmax = (NDADDR + NINDIR (SUPERBLOCK)) * SUPERBLOCK->fs_bsize;
214 return 1;
215 }
216
217 /* continue with file/directory name interpretation */
218
219 while (*dirname == '/')
220 dirname++;
221
222 if (!(INODE->i_size) || ((INODE->i_mode & IFMT) != IFDIR))
223 {
224 errnum = ERR_BAD_FILETYPE;
225 return 0;
226 }
227
228 for (rest = dirname; (ch = *rest) && !isspace (ch) && ch != '/'; rest++);
229
230 *rest = 0;
231 loc = 0;
232
233 /* loop for reading a the entries in a directory */
234
235 do
236 {
237 if (loc >= INODE->i_size)
238 {
239 #if 0
240 putchar ('\n');
241 #endif
242
243 if (print_possibilities < 0)
244 return 1;
245
246 errnum = ERR_FILE_NOT_FOUND;
247 *rest = ch;
248 return 0;
249 }
250
251 if (!(off = blkoff (SUPERBLOCK, loc)))
252 {
253 block = lblkno (SUPERBLOCK, loc);
254
255 if ((map = block_map (block)) < 0
256 || !devread (fsbtodb (SUPERBLOCK, map), 0,
257 blksize (SUPERBLOCK, INODE, block),
258 (char *) FSYS_BUF))
259 {
260 errnum = ERR_FSYS_CORRUPT;
261 *rest = ch;
262 return 0;
263 }
264 }
265
266 dp = (struct direct *) (FSYS_BUF + off);
267 loc += dp->d_reclen;
268
269 #ifndef STAGE1_5
270 if (dp->d_ino && print_possibilities && ch != '/'
271 && (!*dirname || substring (dirname, dp->d_name) <= 0))
272 {
273 if (print_possibilities > 0)
274 print_possibilities = -print_possibilities;
275
276 print_a_completion (dp->d_name);
277 }
278 #endif /* STAGE1_5 */
279 }
280 while (!dp->d_ino || (substring (dirname, dp->d_name) != 0
281 || (print_possibilities && ch != '/')));
282
283 /* only get here if we have a matching directory entry */
284
285 ino = dp->d_ino;
286 *(dirname = rest) = ch;
287
288 /* go back to main loop at top of function */
289 goto loop;
290 }
291
292 int
ffs_embed(int * start_sector,int needed_sectors)293 ffs_embed (int *start_sector, int needed_sectors)
294 {
295 /* XXX: I don't know if this is really correct. Someone who is
296 familiar with BSD should check for this. */
297 if (needed_sectors > 14)
298 return 0;
299
300 *start_sector = 1;
301 #if 1
302 /* FIXME: Disable the embedding in FFS until someone checks if
303 the code above is correct. */
304 return 0;
305 #else
306 return 1;
307 #endif
308 }
309
310 #endif /* FSYS_FFS */
311